Air-compressor



(No Model.) 5 Sheets-Sheet 1.

G. E. DOW.

AIR COMPRESSOR- No. 341,099. Patented May 4, 1886.

FlG-l WWW (No Model.) 5 Sheets-Sheet 2. G. E. DOW.

AIR COMPRESSOR. No. 341,099. Patented May 4, 1886.

FlG.2.

(No Model.) 5 Sheets-Sheet 3.

G. E. DOW.

AIR COMPRESSOR.

No. 341,099. Patented May 4-, 1886.

(No Model.) I 5 Sheets-Sheet 4. G. E. DOW.

AIR COMPRESSOR.

Patented May 4, 1886.

(No Model.) 5Sheets-Sheet 5.

G. E. DOW.

V AIR COMPRESSOR.

No. 341,099. Patented May 4, 1886.

UNITED STATES PATENT OFFICE.

GEORGE DWIN now, OF SAN FRANCISCO, CALIFORNIA.

AIR-COMPRESSOR.

SPECIFICATION forming part of Letters Patent No. 341,099, dated May 4,1885.

Application filed November 9, 1885. Serial No. 182,305. (No model.)

the city and county of San Francisco, State of California, have inventedan Improvement in Air-Compressors; and I hereby declare the following tobe afull, clear, and exact description of the same.

My invention relates to certain improvements in compressors for air orgas, and is particularly applicable to that class in which the medium iscompressed in two or more stages by means of receiving and deliverycylinders,in each of which the compression is partially performed.

It consists of comprcssing-cyliuders having their axes in the same lineand thepistons connected with the piston-rod in such a manner as to beactuated simultaneously, so that no stuffing-boxes are exposed to theheat arising from final compression.

It also consistsin an improved means for surface cooling, and in certaindetails of construction, all of which will be more fully explained byreference to the accompanying drawings, in which- Figure l. is alongitudinal section of my improved compressor. Fig. 2 is an enlargedlongitudinal section of one cylinder with valves, passages, andwater-jacket. Fig. 3 is a view of the receiving end of the cylinder,showing ahalf-section through line N 0, Fig. 2, the piston beingremoved. Fig. 4 is aview of the delivery end of the cylinder, showing ahalfsection through 1 Q, Fig. 2, the piston being removed. Fig. 5 is amodification of the cylinder A, showing the eduction-valves of thereceiving-chamber A placed in the piston. Fig. 6 is a modificationshowing the series of cylinders placed side by side, the pistonsoperated by a rotating shaft having cranks set opposite each other, sothat the pistons operate coincidently and in opposite directions.

A A are two cylinders, having ends A and A, of diii'erent diameters,their axes being in the same line, so that their pistons B and B may beconnected together and operate simultaneously.

av is the piston-rod, extending through the receiving ends of thecylinders A and connecting with their pistons. In the present case Ihave shown a steam'engine, K, placed in line between the two cylinders,so that the pistonrod extends into the engine-cylinder and is connectedwith its piston, thus enabling the single engine to operate bothcompressing-pistons at once. 1

O G are the induction-pipes through which air or other medium isadmitted to the receiving endsof the cylinders A,passing through theinwardly-opening valve L, when the piston moves toward the opposite endof the cylinder. When the piston returns, the valve L closes and thevalve M opens, allowing the ai r or medium which is being compressed topass through the pipe D and into the pipe J, and thence through E intothe intermediate chamber.

Both cylinders A are surrounded by chain bersS and B, through whichwater is caused to circulate by means of pipes V, so as to convey awaythe heat developed by the compression of the air or other medium.\Vithin the chamber B,which surrounds the cylinder A are concentricpipes G and H,arranged in rows, as shown in Fig. 4, so that the watercirculates around them. The air or gas passing from the intermediatechamber into the smaller or discharge end of the opposite cylinder isconducted through cooling-tubes G- and H, so that the heat resultingfrom the first compression will be taken up and conveyed away by thepassing water.

The pistons in each of the cylinders A A are formed with a large and asmall end, the large end fitting the larger portion of the cylinder andthe smaller end fitting the smaller portion. These two are united by aweb or hollow and open connecting portion, so that they operatetogether, and thevalve '1 opens through the smaller end of the pistoninto the discharge end of the chamber A-.

The pipe J connects the two pipes D, which lead from thevalves Minto thereceiving ends of the cylinders, and also, extending beyond these pipes,connects with the pipes E, which open into an annular space, F,surrounding each cylinder between the larger and smaller portionthereof.

The exterior pipes, H, of the cooling system are secured into holes inthe side of the annular chamber F nearest the surrounding space R of thesmaller portion of the cylinder, and they extend nearly to the end ofthis space, and themselves have their outer ends closed, as shown.

The smaller and inner pipes, G, pass through the chamber F, screwinginto the opposite wall and opening into the intermediate chamber orspace between the larger and smaller ends of the piston. These smallerpipes extend concentricall y within the larger ones, H, and nearly totheir closed ends, so that when the piston in the larger portion of thecylinder is moving toward the rear end it forces the air behind itthrough the inner tubes, G, thence back between the tubes G and H andinto the annular space F, from which it escapes through the pipe E. Aswater is freely admitted into the chamber It, within which thesenumerous tubes are situated, it will be seen that the heat developed inthe compression of the air will be nearly or quite all conveyed away bythe water.

The operation of the apparatus will then be as follows: Supposing thepistons to be moving toward the right in the direction shown by thearrows, Fig. 1, the larger portion of the right-hand cylinder will bereceiving air upon one side of the piston through the valve L and thepipe 0. The air which is upon the opposite side of this larger portionof the piston will be forced through the tubes G and H, and thence intothe pipe E and the pipe J, as be fore described, passing along the pipeJ until it meets the air which is being forced through the pipe I) ofthe left-hand cylinder byits piston, which is also moving toward theright and discharging air through the valve M, as shown. These twobodies of air, uniting, continue on through the pipe E, and through thepipes H and G in the chamber R of the lefthand cylinder, entering thespace behind the larger portion of the piston of the cylinder. As thisamount of air is more than is necessary to fill the larger portion ofthe cylinder, the surplus escapes through the valve T in the smaller endof the piston into the discharging end A of the left-hand cylinder. Atthe same time the air contained in the discharge end of the right-handcylinder is being compressed and forced outward through the valve U andthe pipe I to the receiver or point of consumption. \Vhen the movementsof the pistons are reversed, the same action takes place in the reversemanner-that is, the air is admitted into the receiving end of thelefthand cylinder, and is forced from the inter mediate chamber throughthe cooling-pipes and the pipes E and J into the intermediate chamberand the discharge-chamber of the right-hand cylinder, this, operationbeing con tinued at each reciprocation of the pistons. As a quantity ofair equal to the contents of the chamber A must be compressed into thechamber A of the opposite cylinder from the intermediate chamber witheach displacement, it will be seen that the compression created in thereceiving-chamber is a fixed quantity, and is governed by the relativevolume of the two chambers A A The intermediate chambers of thecylinders being maintained in communication with each other by means ofthe pipe or conduit J, the air or gas, in passing into the latter on itsway from one chamber to the other, is conducted through thecooling-tubes G and H, as before described, so that the heat resultingfrom the first compression is taken up by the surrounding water.

The apparatus here described is simple in construction, not liable toderangement or excessive wear, and high speeds may safely be employedwithout injury to the machine, as no liquids are used in the cylindersto take up the heat of compression, as in other machines. The perfectcooling of the air or gas by the means shown and described andsubdividing the work into two or more stages gives ample time to take upthe heat in the jackets, and greatly reduces the amou nt of resistanceoffered to the compression, and consequently takes less power to run themachine.

The compressor requires but two piston-rod stuffing-boxes, each one ofwhich is easily maintai ned, as the piston-rod passes into thereceiving-chamber only, where the pressure and heat is low, no matterhow high the final pressure may be, and the packing is not exposed tothe numerous difficulties arising from exposure to high pressure andtemperature, as in dry compressors of the ordinary construction.

Although I prefer thergeneral arrangement of parts and method ofoperation herein shown, I do not Wish to limit myself to this preciseconstruction, as other arrangements of cylinders, valves, or passagesmay be easily substituted without departing from the essential featuresof the invention. Thus the cylinders might be set side by side and thepistons operated by a rotating shaft having cranks set opposite to eachother, so that the pistons may move coincidently and in oppositedirections.

A modification of the cylinder is shown in Fig. 5, in which theeduction-valves M of the receiving end of the cylinder are placed in thelarge end of the piston, thus dispensing with the passage D.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. The combination, in an air-compressor, of two or more sets ofcylinders, each set comprising two cylinders of unequal size placed inline and having their pistons united so as to move simultaneously,piston-rods extending through the outer heads of the larger cylindersand connected with a driving mechanism, valves through which air may beadmitted and discharged at this end of the larger cylinder, and pipesconnecting the spaces upon opposite sides of the larger pistons witheach other, and also with those of the corresponding series,substantially as herein described.

2. The combination, in an air-compressor, of two or more sets ofcylinders, each set conr prising two cylinders of unequal size placed inline, and communicating freely with each IIO other at their adjacentends, pistons fitting the two cylinders and connecting with each other,so as to move simultaneously, the piston-rods connecting with the largerpistons and extending through the outer heads of the same, so as to beactuated by a suitable motor, induction and eduction valves within theouter head, through which air is admitted to and discharged from theouter side of the larger piston, pipes connecting the discharge-valveswith the spaces between the larger and the smaller pistons of twocorresponding sets of cylinders, and valves by which the air may passfrom this space through the smaller pistons to the outer endsof thecylinders, in combination with discharge or eduction valves connectingthe outer ends of the smaller cylinders with the storage-reservoir,substantially as herein described.

3. The combination, in an :aircompressor, of cylinders arranged in setsof two or more, each set comprising two cylinders of unequal diameterplaced in line, having their adjacent ends open to communicate freely,pistons fitting these cylinders and united, so that they movesimultaneously, induction and eduction valves in the outer head of thelarger cylinder, pipes connecting the eduction-valves of each of thelarger cylinders with the space at the rear of its piston, also with therear of the corresponding piston of its series in the other cylinder, incombination with a series of concentric pipes, through which the airpasses before entering these interior chambers, said pipes beingsurrounded by a chamber through which water circulates, substantially asherein described.

4. The combination, in an air-compressor, of the cylinders connectedtogether in series, each set comprising two cylinders of unequaldiameter standing in line, with their adjacent ends opening into eachother, having pistons connected together, so as to operatesimultaneously, with induction and eduction valves and connecting-pipes,as shown, in combination with a chamber concentric with and exterior tothe smaller cylinder, a'series of concentric pipes extending into thischamberiand connected with the airconducting pipes and passages, so thatthe air must pass through these cooling-pipes, substantially as hereindescribed.

5. The combination, in an air-compressor,

of cylinders arranged in sets of two or more, acting in unison, each setcomprising two cylinders of unequal diameter placed in line, havingtheir adjacent ends open to communicate freely, pistons fitting thesecylinders and united to move simultaneously, induction and eductionvalves in the outer head of the larger cylinder, pipes connecting theeduction-valves of each of the larger cylinders with the space betweenthe larger and smaller pistons of both sets of cylinders, valves openingthrough the smaller pistons into the outer ends of their cylinders, andeduction-valves through the ends of these cylinders for the discharge ofthe compressed air, substantially as herein described.

6. The sets of air compressing cylinders acting in unison, each setcomprising two cylinders of unequal diameter placed in line, with theiradjacent ends open to communicate free- 1 y, and with pistons united tomove simultaneously, chambers surrounding these cylinders at theirjunction, into which the air-conveying pipes open, water-chamberssurrounding the smaller cylinders adjacent to the air-chambers, andpipes extending from the air-chambers into these water-chambers, andother smaller pipes passing through the air-chambers into the largerpipes, and connecting with the larger cylinders in the rear of theirpistons, substantially as herein described.

In witness whereof I have hereunto set my hand.

v GEORGE EDXVIN DOYV. lVitnesses:

O. D. OoLE, J. H. BLooD.

